The ability to thermally shape and form thin glass sheets is increasingly relevant to various industries, such as the automotive industry. The production of glass panes for automobiles is a complex process, which is constantly changing due to increasingly stringent environmental and safety requirements. The demand for intricate glass shapes with high optical quality and low weight is growing as governmental regulations require increased fuel economy and reduced emissions. The ability to make automotive parts from thinner glasses may translate to lower vehicle weight, improved fuel economy, reduced emissions, and/or improved vehicle weight distribution (e.g., lower center of gravity).
Prior art methods for shaping glass include placing glass sheets on a roll conveyor, conveying the glass through a furnace to heat and soften the sheets, and positioning the softened glass below a shaping mold, where it is lifted upward by a lift jet array to contact the shaping mold. The shaping mold serves as a surface around which the glass sheet can be formed to the desired shape. The lift jet array pattern is typically different for different shapes and/or parts and may include non-adjustable, fixed diameter/orifice nozzles and/or adjustable threaded nozzles. The nozzles are positioned below the rollers and blow controlled and focused streams of heated air up between the rollers.
Conventional lift jet systems work well with traditional glasses, which are thicker, such as soda-lime glasses having a thickness ranging from about 3 mm to about 6 mm. Thicker glass sheets can generally withstand the pressure from the nozzles without suffering from local deformations. However, when thinner glasses (e.g., thicknesses less than about 3.0 mm, between about 0.3 mm and about 2.0 mm, between about 0.5 mm and about 1.5 mm, and all ranges and subranges therebetween) are processed using these traditional lift jet systems, the glass tends to distort and bend between each nozzle due to the localized upward force from the nozzles.
Accordingly, it would be advantageous to provide methods and systems for shaping and tempering thinner glass sheets, more specifically a lift jet array that more evenly distributes the upward lifting force over a greater surface area so as to reduce and/or eliminate glass distortion. To reduce manufacturing costs and/or processing times, it would additionally be advantageous to provide a system that can function, at least in part, in conjunction with existing systems for bending and tempering traditional (e.g., thicker) glasses.